Operational Trans conductance Amplifier (OTA) is one of the most versatile and important circuit components in the analog and mixed signal circuit design. OTA is voltage control current source device. In this book, we are shows simple designing of schematic circuit and CMOS Layout of OTA and get parameters like gain margin, phase margin, slew rate, CMRR, Transient Time, Noise Spectral Density, PSRR, Power Dissipation and Power Consumption.